Abstract: Geological conditions, in particular temperature and pressure, are favorable for gas hydrate accumulation in the Shenhu area on the northern slope of the South China Sea. Source rocks having great potential for gas-generation and effective pathways for hydrocarbon migration are available as well. However, drilling results suggest that great difference occurs in different locations in the Shenhu area in terms of gas hydrate accumulation. So far the mechanism and control factors have remained unknown. In this paper, data from 8 drilling wells, including seismic, logging, drilling and geochemical data, are collected and a comparative study conducted on gas hydrate accumulation conditions for both the succeeded and failed wells in order to find the reason for the different distribution of natural gas hydrate in the Northern South China Sea.